Preheat your oven to 160 C / 325 F. Line a baking sheet with parchment or grease it with butter.
Sift or whisk together the flour, corn flour , coffee and salt.
Beat the butter and sugar together with an electric mixer or a wooden spoon until light and fluffy.
Add the dry ingredients and beat until it comes together. Knead the dough on a floored surface until smooth (takes only a minute or two)
Roll out the dough to about 1 cm thick and cut out desired shapes using a cookie cutter or knife. Reroll scraps and cut until all dough is shaped.
Place the shaped dough on the prepared baking sheet , leaving about 2 cms gap between each. Chill for 30 minutes.
Bake at 160 C/ 325 F for 15-16 minutes until the cookies brown around the edges.
Cool for a minute on the pan , then transfer to a wire rack to cool completely.
Melt your chocolate in a double boiler or microwave. Dip half of each cooled cookie and let dry on parchment paper or silicon mat.